1. Field of the Invention
The present invention relates to liquid crystal displays, and more particularly, to a driving circuit for a display panel capable of actively controlling a gamma characteristic and the viewing angle of an output image according to a user's preference and/or environment, a liquid crystal display having the driving circuit and a method for driving the liquid crystal display.
2. Description of the Related Art
A typical liquid crystal display (LCD) includes an LCD panel, having an upper substrate with color filters and a common electrode formed thereon, and a lower substrate with thin film transistors and pixel electrodes formed thereon, and a liquid crystal layer interposed between both the substrates, and a backlight as a light source positioned behind the LCD panel. Further, a polarizer may be attached to a surface of the LCD panel to control the transmissivity of light from the backlight exiting the liquid crystal layer.
An image displayed on such a conventional LCD has predetermined fixed gamma and viewing angle characteristics, which depends upon a gray scale voltage (or gamma voltage) that is referenced to a data signal applied to a pixel electrode.
However, since a reference voltage when generating a gray scale voltage, i.e., a gamma reference voltage GVDD, is fixed at one state (standard state) in a conventional LCD, it is difficult to change the gamma characteristic and the viewing angle of an output image depending on a user's preference and environment. For example, since a characteristic of a favorite image is different depending on a user, the gamma characteristic of an output image is required to be controlled considering a user's preference. Further, in a conventional LCD, a wide viewing angle is typically required to display better an image in terms of enhanced visibility. However, for the protection of a user's privacy in public places, a narrow viewing angle is also required so as not to display an image to others. Therefore, the viewing angle of an output image needs to be adjusted considering a user's preference and environment.